(Reuters) - Italy's biggest commercial broadcaster Mediaset MS.MI holds a shareholder meeting on Friday over governance changes needed to enable a pan-European expansion plan, which its second-largest investor Vivendi VIV.PA is fighting in court.

FILE PHOTO: The Mediaset tower is seen in Cologno Monzese neighbourhood Milan, Italy, in this April 7, 2016. REUTERS/Stefano Rellandini/File Photo

Following are key events in the prolonged dispute:

April 2016 - Vivendi agrees to buy Mediaset’s pay-TV business, billed as a major step in billionaire businessman Vincent Bollore’s plan to build a southern European content and video-on-demand powerhouse. The two companies agree to take a 3.5% stake in each other.

July 2016 - Vivendi backs away from the original deal, proposing an alternative that would give it a bigger direct stake in the broadcaster.

Vivendi says the main reason is the unreliability of Mediaset Premium’s financial forecasts for 2016 to 2018.

The deal falls apart as Mediaset rejects Vivendi’s new proposal and announces legal action against the French group.

Dec. 2016 - Vivendi builds up a 28.8% stake in Mediaset in a move condemned by the Italian broadcaster.

April 2017 - Italy's communications watchdog orders Vivendi, which is also the top shareholder in Telecom Italia TLIT.MI, to cut its stake in either the telecoms group or Mediaset within a year to comply with rules designed to prevent a concentration of power.

April 2018 - Vivendi transfers a 19.19 percent Mediaset shareholding to a trust to comply with the regulator’s ruling.

The legal battle continues on multiple fronts, including a 3 billion euro damages request by Mediaset over the failed pay-TV deal and repeated complaints by Vivendi about not being allowed to exercise its voting rights at Mediaset shareholder meetings.

Sept. 2019 - Mediaset shareholders back a plan to create a pan-European media group under a new Dutch holding, fending off opposition from Vivendi.

Under the plan, both Mediaset and its Spanish unit will be merged into a Dutch holding company MediaForEurope (MFE).

Vivendi, which says the new structure tightens Fininvest’s grip, challenges the plan in court in Spain and Italy.

Oct. 2019 - A Spanish court suspends Mediaset’s corporate overhaul, ruling in favor of Vivendi. Mediaset appeals.

Nov. 2019 - Mediaset and Vivendi fail to hammer out a deal by a court-imposed deadline to end their legal stand-off.

Dec. 2019 - A Milan court postpones a decision on Vivendi’s request to suspend Mediaset’s corporate overhaul until Jan. 21 at the earliest, leaving the reorganisation on hold.