A month after emerging as the top vote-getter in the November municipal election, Republican Catherine Walsh on Thursday was elected the new chairwoman of the Planning and Zoning Commission.

Walsh succeeds Democrat Ron Corwin, who served as chairman since 2007. She was appointed to the P&Z in 2008 following the resignation of Helen Martin Block. Walsh also works as a consultant in the steel industry, specializing in domestic and international trade.

The P&Z's three other Republicans -- Jack Whittle, Chip Stephens and Al Gratrix -- voted for Walsh as chairwoman. Corwin and the P&Z's two other Democrats, Nora Jinishian and Howard Lathrop, abstained.

Walsh's election to the top P&Z seat reflects the GOP's ascendancy in town government, when it regained control of the P&Z and the Board of Finance in the November election. Walsh and her three Republican colleagues were each elected to their first terms last month, which guarantees Republican control of the commission until 2015.

Whittle was chosen vice chairman, while Stephens assumed the commission's secretary post. Votes for both of those positions also split along party lines -- the P&Z's four Republicans voted for Whittle and Stephens, while the three Democrats abstained two more times.

The election of P&Z alternates produced a more pronounced partisan division when Democrats objected to a Republican proposal to suspend the past practice for reviewing alternate candidates and to instead move directly to a vote on those positions. For previous alternate openings, the P&Z had interviewed candidates in a public session, then discussed alternate nominees in an executive session, and voted on the nominations in another public session.

"To come in and suggest that we change the way that this commission has been handling this by changing the rules is a questionable way to proceed," Corwin said.

The Republicans' revised process for voting on P&Z alternates adhered to P&Z by-laws, as well as Robert's Rules of Order, the parliamentary procedure guidelines that govern P&Z meetings, according to Walsh.

"There was nothing in either document that suggested that we couldn't do this," she said.

The Republicans also argued that the past experience of their two nominated alternates -- Republicans Tim Wetmore and Michael Krawiec -- warranted the procedural change. Krawiec served on the P&Z from 2007 until last month; he did not seek re-election in last month's election. Wetmore was appointed to the P&Z to fill a vacancy in 2005 and served until 2007.

Eventually, Krawiec and Wetmore were voted in as alternates by respective margins of 6-1 and 5-2. Despite his opposition to the procedural change, Corwin supported Krawiec and Wetmore's nominations. Fellow Democrat Nora Jinishian voted for Krawiec, but abstained from voting for Wetmore, explaining that she did not know him. Lathrop abstained on both votes.

At the close of the meeting, Walsh took a more conciliatory approach by praising Corwin for his leadership of the P&Z during his tenure as chairman.

"I think you did a phenomenal job," she told him. "I thank you, and the town thanks you."