The low-profile chief of Deepak Fertilisers on Wednesday bought 24.46% shareholding in MCF.
Must satisfy shareholders on game plan to steer UB Group over next 12 months.
UB Group stocks, led by United Breweries Holdings Ltd, on Monday slumped by up to 5.3 per cent as trouble mounted for Vijay Mallya.
The lenders have not ruled out selling the property to recover part of their loans to the company.
The battle for the takeover of MCFL has been going on for one year.
Banks have been struggling hard to recover dues from grounded Kingfisher Air.
The consortium led by SBI has also initiated the process of recovery.
United Bank's exposure to Kingfisher Airlines was around Rs 350 crore (Rs 3.50 billion)
Kolkata-based United Bank of India, which had earlier declared Kingfisher Airlines and its four directors, including Mallya as wilful defaulters, on Tuesday identified UBHL, the guarantor of the grounded Kingfisher Airlines, also a wilful defaulter.
The airline, part of Vijay Mallya-led UB Group, has been grounded since October 2012, after being bogged down by huge and mounting losses.
The agreement says UB Group and Adventz will have the right of first refusal over each other's shares.
If they encash shares, Dutch major Heineken will emerge as single largest shareholder in the company.
Mallya has denied that he had fled India and said he would comply with laws.
In a major clampdown for non-compliance of Listing Agreement, top exchanges BSE and NSE announced suspension of trading in shares of Kingfisher Airlines and another group firm, UB Engineering, from next month.
Vijay Mallya has lost control of his companies.
Few top honchos of India Inc did very well in 2014.