The joint venture between European telecom companies Nokia Corporation and Siemens AG may pressure their North American rivals Motorola Incorporated and Nortel Networks Corporation to finally jump into the consolidation game.

Nokia and Siemens said early yesterday that they are merging their network-equipment businesses into a joint venture. The move follows L.M. Ericsson Telephone Company’s acquisition of Marconi and Lucent Technologies Incorporated’s merger with Alcatel SA as companies increase their size and reach to more effectively compete in a market that features a glut of traditional telecom equipment players; new, more aggressive providers coming out of China; and a shrinking customer base.

Motorola and Nortel stand as the last of the major equipment providers that have yet to participate in a large deal. With consolidation all around them, the two will likely have to make some changes to their businesses.

“We believe a Nokia/Siemens JV would intensify pressure on Motorola and Nortel to increase their respective stakes in networking to solidify their positions or conversely find a way to exit or narrow their focus,” CIBC World Markets Corporation analyst Ittai Kidron said in a note.

The analyst doesn’t own a stake in either company, but his firm is seeking an investment-banking relationship with both.

Nortel spokeswoman Patricia Vernon declined to comment on any future moves. “Industry consolidation is a natural course of business in today’s highly competitive global economy,” she said.

Motorola wasn’t immediately available for comment.

Motorola shares slipped 6 cents to close at $20.02 yesterday on the New York Stock Exchange, where Nortel shares plunged 23 cents, or 10%, to close at $2.04.

Motorola has options. The Schaumburg, Ill.-based company still has a robust wireless-handset business and is less reliant on the telecom- equipment side. Its network segment contributed $1.43 billion in revenue during the first quarter, or roughly 14% of its total revenue of $10.1 billion.

The company can make an acquisition to strengthen its network business, and it had reportedly shown interest in Siemens’ communications business. But Chief Executive Ed Zander has repeatedly expressed his disdain for large deals, saying that few have worked out. The company is more likely to focus on its mobile-handset division or make smaller acquisitions to bulk up its networks division.