An alien bank may purchase, hold and convey real estate for the following purposes and no other:

(1) Such as shall be necessary for the convenient transaction of its business, including with its banking offices other apartments in the same building to rent as a source of income: PROVIDED, That not to exceed thirty percent of its capital and surplus and undivided profits may be so invested without the approval of the director.

(2) Such as shall be purchased or conveyed to it in satisfaction, or on account of, debts previously contracted in the course of business.

(3) Such as it shall purchase at sale under judgments, decrees, liens or mortgage foreclosures, against securities held by it.

(4) Such as it may take title to or for the purpose of investing in real estate conditional sales contracts.

(5) Such as shall be convenient for the residences of its employees.

No real estate except that specified in subsections (1) and (5) of this section may be carried as an asset on the corporation's books for a longer period than five years from the date title is acquired thereto, unless an extension of time be granted by the director.