Nokia ( NOK) and Siemens ( SI) have agreed to combine their telecom-equipment units in a deal valued at about $31.5 billion, according to a media report.

The two companies plan to announce the deal Monday, according to the report, published Sunday evening on The Wall Street Journal's Web site. The report cited unnamed sources familiar with the matter.

Each partner would contribute its network-equipment operations to the new company and take a 50% stake in it, the report said. Nokia would have bigger sway over management, however, getting a majority of board seats and installing its executive Simon Beresford-Wylie as CEO. The venture would also be headquartered in Nokia¿s home country of Finland.

The telecom industry has undergone rapid consolidation in the past few years, but both Nokia and Siemens had stayed away from big deals.

Nokia lost 43 cents in New York trading Friday to close at $19.97. Siemens lost 84 cents to finish at $79.80.